1. Field of the Invention
The present invention relates to a vehicular light source unit using an LED element mounted on a circuit board as a light source.
2. Related Art
In vehicular marker lamps and the like that have an LED as a light source, a plurality of LEDs are generally mounted on a metal substrate by soldering or caulking. However, heating the LED generally reduces a luminous flux thereof. Therefore, soldering to the substrate heats the LED and adversely affects the luminous flux of the LED. Mounting by soldering and caulking also requires dedicated equipment that increases the cost of mounting. In addition, current LEDs have weak luminous flux per lamp, so the plurality of LEDs must be quickly mounted by soldering and the like. If the luminous flux of the LED can be improved, then only one LED need be adopted as the light source. Therefore, a low-cost mounting method for attaching an LED to a substrate without soldering equipment or a caulker would be useful.
Patent Document 1 (Japanese Patent Application Laid-Open (Kokai) No. JP-A-2004-172032) below discloses a structure in which an LED is mounted on a molding substrate. In the molding substrate described in Patent Document 1, a current-flowing portion formed of a conductive resin material is integrated on an upper surface of an insulating portion formed of an insulating resin agent. The insulating portion of the molding substrate is integrally formed with a pair of right and left latch pieces. The pair of right and left latch pieces projects upward from the current-flowing portion and has a projecting portion facing downward. Meanwhile, the LED described in Patent Document 1 is provided with a pair of right and left band plate-like connector terminals on both sides of a main body portion that has a light emission portion. The connector terminal is provided with a hole for engaging with the projecting portion.
The pair of right and left connector terminals of the LED is inserted into a space between the conductive current-flowing portion and the insulating latch portion of the molding substrate. In addition, the projection of the latch portion is engaged with the hole of the connector terminal. Accordingly, the LED is fixed to the molding substrate.
[Patent Document 1] Japanese Patent Application Laid-Open (Kokai) No. JP-A-2004-172032